α -nucleus optical potentials from chiral effective field theory NN interactions

We present a determination of optical potentials for He-target collisions using the double-folding method. We use chiral effective field theory nucleon-nucleon interactions at next-to-next-to-leading order combined with state-of-the-art nucleonic densities. The imaginary part of the optical potential is obtained from the real double-folding interaction either through a proportionality constant or applying Kramers-Kronig dispersion relations. With these potentials, we compute the elastic scattering of He off various targets, from He to Sn. We study the sensitivity of our predicted cross sections to the choice of nucleon-nucleon interactions and nuclear densities. Very good agreement is obtained with existing elastic-scattering data for He energies between 100 and 400 MeV.